I think one of the difficulties is that in a short space of time it's hard to get everyone up to speed on a complex body of code. So I can understand why training courses are somewhat forced to revert to smaller examples that everyone can get in their heads quickly - otherwise you would spend a huge chunk of time understanding the code base.

For me it wasn't really about the code itself, it was more about learning the process of breaking problems down and then applying different refactoring techniques to increase the abstraction.

One of the best parts of the class was the discussions/code reviews and Sandi really does knows her stuff. My classmates and I had many deep discussions with her on a wide range of topics and she was always able to explain things in a clear and concise way.

Perhaps if you are a senior ruby developer of many years experience this course wouldn't be the best investment but I would definitely recommend it for junior/mid range developers.